Ammonia-based, imide-containing resin cuts of styrene-maleic resins

ABSTRACT

A process of preparing an aqueous solution of a cycloimide-containing polymer includes heating an aqueous solution of a cycloanhydride-containing polymer with a first neutralizing agent at a ratio of cycloanhydride to neutralizing agent of about 1:1 to about 1:1.5 at a temperature and for a time sufficient to form the aqueous solution of the cycloimide-containing polymer having a cycloimide to acid group ratio of about 1:2 to about 1.5:2.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 15/777,150 filed on May 17, 2018, which is a U.S. National PhaseApplication under 35 U.S.C. § 371 of International Application No.PCT/US2016/061872, filed on Nov. 14, 2016, which claims the benefit ofand priority to U.S. Provisional Application No. 62/257,527, filed onNov. 19, 2015, the contents of which are incorporated herein in theirentireties.

FIELD

The invention generally relates to the preparation of aqueous solutionof styrene-maleic-acrylic resins, and, in particular their use assupport resins.

SUMMARY

In one aspect, provided herein are processes of preparing an aqueoussolution of a cycloimide-containing polymer, the process including:heating an aqueous solution of a cycloanhydride-containing polymer witha first neutralizing agent at a ratio of cycloanhydride to neutralizingagent of about 1:1 to about 1:1.5 at a temperature and for a timesufficient to form the aqueous solution of the cycloimide-containingpolymer having an imide to starting anhydride ratio of about 1:2 toabout 1.5:2. In some embodiments, the temperature is about 130° C. toabout 155° C. In some embodiments, the ratio of cycloanhydride toneutralizing agent is about 1:1, and the cycloimide to acid group ratiois about 1:2. In some embodiments, the cycloanhydride-containing polymeris a styrene-maleic anhydride polymer. In some embodiments, thestyrene-maleic anhydride polymer has a ratio of styrene to maleicanhydride of from about 1:1 to about 3:1. In some embodiments, thecycloanhydride-containing polymer further contains acrylate,methacrylate, or diisobutylene repeat units, or a combination of any twoor more thereof. In some embodiments, the process further containsadding a second neutralizing agent to the aqueous solution of thecycloimide-containing polymer at a temperature of less than about 90° C.to form a neutralized polymer. In some embodiments, the firstneutralizing agent is an amine represented by the formula NR²R³R⁴,wherein R², R³, and R⁴ are independently H, C₁₋₁₂ alkyl, or C₁₋₁₂ aryl.In some embodiments, the first neutralizing agent is NH₃. In someembodiments, the second neutralizing agent is an alkali metal hydroxide,alkali metal oxide, alkaline earth metal hydroxide, alkaline earth metaloxide, or an amine represented by the formula NR²R³R⁴, wherein R², R³,and R⁴ are independently H, C₁₋₁₂ alkyl, or C₁₋₁₂ aryl. In someembodiments, the second neutralizing agent is NaOH, KOH, or NH₃. In someembodiments, the time is from about 1 hour to 5 hours. In someembodiments, the aqueous solution has a pH of from about 7 to about 10.In some embodiments, the imide-containing polymer has a number averagemolecular weight from about 5,000 g/mol to about 15,000 g/mol. In someembodiments, the aqueous solution of the cycloimide-containing polymerhas a viscosity from about 10 cPs to about 500,000 cPs. In someembodiments, the aqueous solution of the cycloimide-containing polymerhas a viscosity from about 10 cPs to about 5,000 cPs. In someembodiments, the cycloimide-containing polymer has a Tg from about 150°C. to about 230° C. In some embodiments, the cycloimide-containingpolymer is present in the aqueous solution from about 10 wt % to about35 wt %. In some embodiments, the cycloimide-containing polymer ispresent in the aqueous solution from about 25 wt % to about 30 wt %.

In another aspect, provided herein are aqueous solutions of acycloimide-containing polymer prepared according to the processdescribed herein. In some embodiments, the aqueous solution exhibits anincrease in viscosity of less than 20% at ambient temperature for 90days relative to the viscosity of the aqueous solution upon itspreparation.

In another aspect, provided herein are aqueous compositions containing

-   -   (a) a solubilized cycloimide-containing resin formed from        comonomers including maleic anhydride and substituted ethylenic        comonomers, wherein        -   (i) the resin includes a partially neutralized            maleamide-acid species; and        -   (ii) the resin has an oxygen content of from about 5% to            about 30%, an acid value of at least 60 mg KOH/g on dry            solids, and an amine base value of at least 60 mg/KOH on dry            solids;        -   (iii) the resin has a number average molecular weight of            about 1,000 D to about 10,000 D; and        -   (iv) the substituted ethylenic comonomers include styrene;            and    -   (b) emulsion particles which constitute 0-80% weight of the        total solids.        In some embodiments, the ratio of styrene to maleic anhydride in        the average molar repeat unit of the resin is from 1:1 to 5:1.        In some embodiments, the substituted ethylenic comonomers        further include C₆-C₂₀ α-olefins; the resin has a percentage of        styrene in the comonomer repeat unit of from 0% to 80%; and        maleic anhydride is 33% to 50% of the average molar repeat unit        of the resin. In some embodiments, the resin further contains        hydrolyzed diacid; the maleamide-acid species is partially        neutralized by a neutralizing amine; the neutralizing amine        contains ammonia or a primary amine; and the resin has a degree        of neutralization of the maleamide-acid species and the        hydrolyzed diacid of at least 50%. In some embodiments, the        resin has a degree of imidization of from about 25% to about 75%        relative to the amount of maleic acid monomer present in the        resin. In some embodiments, the resin has a degree of        imidization of from about 25% to about 50% range relative to the        amount of maleic acid monomer present in the resin. In some        embodiments, the resin is formed from comonomers including        acrylic acid, methacrylic acid, styrene, alpha-methyl styrene        and maleic anhydride. In some embodiments, the emulsion        particles are formed from initial polymerization of acrylate and        styrenic monomers in the presence of a surfactant prior to        blending with the resin. In some embodiments, the emulsion        particles are formed from polymerization of acrylate and        styrenic monomers in the presence of the resin.

In another aspect, provided herein are processes of preparing a resincut, the process including cutting a resin at a temperature of between80° C. and 150° C. by introducing the resin to an initial charge ofneutralizing amine of from 30% to 80% based on diacid equivalent ofmaleic anhydride units in the resin, wherein the resin is formed fromcomonomers including maleic anhydride and styrene; and the resin cut iswater-soluble. In some embodiments, 25% to 75% of the maleic anhydrideunits are imidized. In some embodiments, 25% to 75% of the maleicanhydride units are imidized, and the resin cut has a resultant degreeof neutralization of any carboxyl species of from 50% to 100%.

BRIEF DESCRIPTION OF THE DRAWINGS

The FIGURE is a dual axis graph of the viscosity and pH versus degree ofneutralization (DN) curves, according to Example 1.

DETAILED DESCRIPTION

Various embodiments are described hereinafter. It should be noted thatthe specific embodiments are not intended as an exhaustive descriptionor as a limitation to the broader aspects discussed herein. One aspectdescribed in conjunction with a particular embodiment is not necessarilylimited to that embodiment and can be practiced with any otherembodiment(s).

As used herein, “about” will be understood by persons of ordinary skillin the art and will vary to some extent depending upon the context inwhich it is used. If there are uses of the term which are not clear topersons of ordinary skill in the art, given the context in which it isused, “about” will mean up to plus or minus 10% of the particular term.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the elements (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the embodiments and does not pose alimitation on the scope of the claims unless otherwise stated. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential.

The present application is directed to rheologically stable compositionsthat are based on maleic co-polymers, as well as methods for such resincompositions. The maleic co-polymers are cut in water with ammonia in acontrolled manner so as to form preferential amounts of imide and fullyhydrolyzed species, with minimal formation of the amide-acid species.

The methods include producing high-imide-containing resin cuts of vinylmonomer-maleic anhydride resins which exhibit good stability, excellentheat-resistance, and are substantially free of half-amide/half-acidspecies. Such resin cuts may find utility as resin-supports forsecondary monomer polymerization. For example, such resins may be usefulin rheology-controlled technologies.

Prior to discussing the process provided herein, a discussion of theconventional process is appropriate here. Aqueous resin cuts of α-olefinor vinyl monomer/maleic anhydride resins can be made using commonneutralizing bases, such as ammonia or sodium hydroxide. Products of theresulting cuts generally offer heat-resistant compositions, and they areuseful for water-based overprint varnishes and inks. For example, theymay find use in inks and coatings for pre-printed corrugated boards.While sodium cuts tend to be too hydrophilic, leading to inferior waterresistance, the films made from emulsions made with ammonia-neutralizedcuts undergo ring closure upon heat exposure, effectively re-making thecomposition more hydrophobic. When made conventionally with a 2:1 ratioof ammonia:anhydride at about 90° C. and 1 atm, ammonia-neutralizedresin cuts result in opening of the anhydride group into an amide andacid group (half amide/acid species), where the acid group is in theform of an ammonium carboxylate salt. Upon application, the ammoniumsalt will slowly decompose at room temperature. At modest temperatures(approximately 130° C.), further chemistry may occur, such as theamide-acid species undergoing ring-closure.

FTIR has shown that both imide (when water is the leaving group) andanhydride (when ammonia is the leaving group) form at elevatedtemperature. The formation of imide leads to an increase in Tg becausethe imide species is capable of intermolecular hydrogen-bonding. Forinstance, the resin SMA-1000 (a 1:1 STY-MAH composition) has a Tg of155° C. in the anhydride form; upon making an ammonia cut (2:1ammonia:anhydride) and full ring-closure, the Tg increases to 192° C.Because anhydride groups are capable of being H-bond acceptors, there islittle further increase in Tg for greater than 50 mol % imide content.The imide therefore confers certain beneficial properties includingdecreased water resistance, improved heat-resistance, and potentiallybetter adhesion on hydrophobic surfaces.

A critical problem is that direct in-situ imidization can occur alreadyin aqueous solution with time, heat, or both. Thus, ammonia cuts ofvinyl monomer/α-olefin [(styrene, diisobutylene)-MAH (maleic anhydride)]begin to ring-close at temperatures as low as 55° C., possibly lower.For instance, it has been found that the acid value (AV) for a 60/40blend of SMA-2000/SMA-1000, which should have a starting anhydride value(mg KOH/g dry) of 220 on solids, and thus an initial acid value of 220as well, drops with additional cook time. For instance, at 93° C., theAV is reduced from 209 to 193 in extending the cook time from 4 hours to7 hours. This small drop in acid value is the result of direct imideformation from the half amide-half acid species. This process results ina disproportionately large change in rheology as the viscosity increases100-fold during this time. We note that cooking these solutions to 15hours and 24 hours results in AVs of 170 and eventually 140, and theviscosity continues to increase. Importantly, it was noted that inthree-week heat-aging tests at 55° C., 4 hour cuts undergo unacceptablechanges in viscosity, and that even at room temperature over longperiods of time, we may find instability as well.

The conventional process may be described, without being bound bytheory, by the illustration of Scheme 1. In Scheme 1, a ratio of 2:1ammonia:anhydride is used resulting in ring opening to a fullyneutralized amide-acid intermediate. Continued heating may lead to ringclosure to a cycloimide-amide-acid resin, which over time increases inviscosity.

It has now been found that incorporation of pre-formed imide in theresin cut improves the heat-resistance over overprint varnishes,especially over aluminum flake inks. Thus, the present method providesfor pre-forming the desired imide content, and then stopping, or atleast substantially abating further imidization within the polymer, toprevent or substantially decrease subsequent increases in viscosityduring the pot life of the resin cut.

It has been surprisingly determined that charging a lesser amount ofamine neutralizing agent, based on anhydride content, and then heatingunder pressure in an autoclave at a temperatures from about 130° C. toabout 155° C. results in a composition that contains the desired amountof imide (approximately 50 mol % on anhydride), the balance containinglittle or no amide but mostly the hydrolyzed dicarboxyl species at amodest degree of neutralization (“DN”), based on the neutralizing agentbalance. Addition of further neutralizing agent at lower temperature(e.g. less than about 90° C.) results in neutralization of the acidgroups, a substantial drop in viscosity, and importantly, no amidecontent in the resin. The resulting neutralized solution is referred toas a “resin cut.” Such resins cuts provide good viscosity stability overtime. Differential scanning calorimetry (DSC) has shown that theresulting species exhibit acceptable Tg increase and heat-resistance.Therefore, we find that it is possible to make resin cuts with highimide content, which provide good heat resistance properties but at thesame time do not have high viscosity during production and viscositystability overtime.

Other advantages include, but are not limited to, reduced productiontimes compared to conventional technologies (e.g. approximately 1 hourat 155° C., or approximately 3 hours at 135° C.); design of newdispersants based on a combination of alkyl amines/ammonia;neutralization and partial neutralization with tertiary amines toimprove adhesion on hydrophobic substrates; faster build-up inheat-resistance due to lower initial salt content; use of the producedresins for novel polymerization support purposes; design of high glasstransition (Tg) resins, and improved adhesion due to the bidentatenature of the resin.

In some embodiments, the resin has an average number molecular weight ofabout 1,000 Daltons (D) to about 10,000 D. This includes an averagenumber molecular weight of about 1,000 D to about 9,000 D; an averagenumber molecular weight of about 1,000 D to about 8,000 D; an averagenumber molecular weight of about 1,000 D to about 7,000 D; an averagenumber molecular weight of about 1,000 D to about 6,000 D; an averagenumber molecular weight of about 1,000 D to about 5,000 D; an averagenumber molecular weight of about 1,000 D to about 4,000 D; an averagenumber molecular weight of about 2,000 D to about 10,000 D; an averagenumber molecular weight of about 2,000 D to about 9,000 D; an averagenumber molecular weight of about 2,000 D to about 8,000 D; an averagenumber molecular weight of about 2,000 D to about 7,000 D; an averagenumber molecular weight of about 2,000 D to about 6,000 D; and anaverage number molecular weight of about 2,000 D to about 5,000 D. Insome embodiments, the average number molecular weight is about 1,000;2,000; 3,000; 4,000; 5,000; 6,000; 7,000; 8,000; 9,000; or 10,000 D,including increments therein.

In another aspect, provided herein are aqueous compositions containing asolubilized resin described herein and emulsion particles. In someembodiments, provided herein are aqueous compositions containing

-   -   (a) a solubilized cycloimide-containing resin formed from        comonomers including maleic anhydride and substituted ethylenic        comonomers, wherein        -   (i) the resin contains a partially neutralized            maleamide-acid species; and        -   (ii) the resin has an oxygen content of from about 5% to            about 30%, an acid value of at least 60 mg KOH/g on dry            solids, and an amine base value of at least 60 mg/KOH on dry            solids;        -   (iii) the resin has a number average molecular weight of            about 1,000 D to about 10,000 D; and        -   (iv) the substituted ethylenic comonomers include styrene;            and    -   (b) emulsion particles which constitute 0-80% weight of the        total solids.

In some embodiments, the ratio of styrene to maleic anhydride in theaverage molar repeat unit of the resin is from 1:1 to 5:1. This includesa ratio of styrene to maleic anhydride in the average molar repeat unitof the resin of from 1:1 to 4:1, from 1:1 to 3:1; and from 1:1 to 2:1.In some embodiments, the ratio of styrene to maleic anhydride in theaverage molar repeat unit of the resin is 1:1, 2:1, 3:1, 4:1, or 5:1,including increments therein.

In some embodiments, the substituted ethylenic comonomers consist of orconsist essentially of styrene. In some embodiments, the substitutedethylenic comonomers further include C₆-C₂₀ α-olefins. In someembodiments, the substituted ethylenic comonomers do not includediisobutylene. In some embodiments, the substituted ethylenic comonomersfurther include C₆-C₂₀ α-olefins and do not include diisobutylene. Insome embodiments, the substituted ethylenic comonomers consist of orconsist essentially of styrene and C₆-C₂₀ α-olefins and do not includediisobutylene.

In some embodiments, the resin has a percentage of styrene in thecomonomer repeat unit of from 0% to 80%. This includes a percentage ofstyrene in the comonomer repeat unit of from 0% to 75%, from 0% to 70%,from 0% to 65%, from 0% to 60%, from 0% to 55%, from 0% to 50%, from 5%to 75%, from 5% to 70%, from 5% to 65%, from 5% to 60%, from 5% to 55%,from 5% to 50%, from 10% to 75%, from 10% to 70%, from 10% to 65%, from10% to 60%, from 10% to 55%, and from 10% to 50%, including incrementalranges therein. In some embodiments, the resin has a percentage ofstyrene in the comonomer repeat unit of about 0, 1, 2, 3, 4, 5, 6, 7, 8,9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44,45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62,63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or80%, including increments therein.

In some embodiments, the resin is formed from comonomers includingacrylic acid, methacrylic acid, styrene, alpha-methyl styrene and maleicanhydride. In some embodiments, the resin is formed from comonomersconsisting essentially of acrylic acid, methacrylic acid, styrene,alpha-methyl styrene and maleic anhydride.

In some embodiments, maleic anhydride is 33% to 50% of the average molarrepeat unit of the resin. This includes ranges of 33% to 45%, 33% to40%, 35% to 50%, 35% to 45%, 35% to 40%, 40% to 50%, or 45% to 50%. Insome embodiments, maleic anhydride is 33%, 34%, 35%, 36%, 37%, 38%, 39%,40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49% or 50%, includingincrements therein, of the average molar repeat unit of the resin.

As used herein, unless otherwise denoted, a “partially neutralized”refers to more than 0% neutralization but less than 100% neutralization.In some embodiments, “partially neutralized” refers to about 1% to about99% neutralization. This includes from about 5% to about 99%neutralization, from about 5% to about 95% neutralization, from about 5%to about 90% neutralization, from about 5% to about 85% neutralization,from about 5% to about 80% neutralization, from about 5% to about 75%neutralization, from about 5% to about 60% neutralization, from about 5%to about 50% neutralization, from about 10% to about 99% neutralization,from about 10% to about 95% neutralization, from about 10% to about 90%neutralization, from about 10% to about 85% neutralization, from about10% to about 80% neutralization, from about 10% to about 75%neutralization, from about 10% to about 60% neutralization, from about10% to about 50% neutralization, from about 20% to about 99%neutralization, from about 20% to about 95% neutralization, from about20% to about 90% neutralization, from about 20% to about 85%neutralization, from about 20% to about 80% neutralization, from about20% to about 75% neutralization, from about 20% to about 60%neutralization, from about 20% to about 50% neutralization, from about30% to about 99% neutralization, from about 30% to about 95%neutralization, from about 30% to about 90% neutralization, from about30% to about 85% neutralization, from about 30% to about 80%neutralization, from about 30% to about 75% neutralization, from about30% to about 60% neutralization, from about 30% to about 50%neutralization, from about 50% to about 99% neutralization, from about50% to about 95% neutralization, from about 50% to about 90%neutralization, from about 50% to about 85% neutralization, from about50% to about 80% neutralization, from about 50% to about 75%neutralization, from about 75% to about 99% neutralization, from about75% to about 95% neutralization, or from about 75% to about 90%neutralization. In some embodiments, “partially neutralized” refers toabout 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55,56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73,74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91,92, 93, 94, 95, 96, 97, 98, or 99% neutralization, including incrementstherein. In some embodiments, “partially neutralized” refers to at leastabout 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55,56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73,74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91,92, 93, 94, 95, 96, 97, 98, or 99% neutralization. In some embodiments,the percentage of neutralization is referred to as degree ofneutralization.

In some embodiments, the maleamide-acid species is partially neutralizedby a neutralizing amine. In further embodiments, the neutralizing amineincludes ammonia or a primary amine. In some embodiments, theneutralizing amine consists essentially of or consists of ammonia or aprimary amine.

In some embodiments, the resin has an oxygen content of about 5% toabout 30%. This includes an oxygen content of from about 5% to about25%, from about 5% to about 20%, from about 5% to about 15%, from about5% to about 10%, from about 10% to about 30%, from about 10% to about25%, from about 10% to about 20%, from about 15% to about 30%, fromabout 15% to about 25%, or from about 20% to about 30%. In someembodiments, the resin has an oxygen content of about 5, 6, 7, 8, 9, 10,11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28,29, or 30%, including increments therein.

In some embodiments, the resin has an acid value of at least 60 mg KOH/gon dry solids. This includes an acid value of at least 65, 70, 75, or 80mg KOH/g on dry solids.

In some embodiments, the resin has an amine base value of at least 60 mgKOH/g on dry solids. This includes an amine base value of at least 65,70, 75, or 80 mg KOH/g on dry solids.

In some embodiments, the resin has a degree of imidization of from about25% to about 75% relative to the amount of maleic acid monomer presentin the resin. This includes a degree of imidization of from about 25% toabout 70%, from about 25% to about 65%, from about 25% to about 60%,from about 25% to about 55%, from about 25% to about 50%, from about 25%to about 45%, from about 25% to about 40%, from about 35% to about 75%,from about 35% to about 70%, from about 35% to about 65%, from about 35%to about 60%, from about 35% to about 55%, from about 35% to about 50%,from about 35% to about 45%, from about 35% to about 40%, from about 50%to about 75%, from about 50% to about 70%, from about 50% to about 65%,or from about 50% to about 60% relative to the amount of maleic acidmonomer present in the resin. In some embodiments, the resin has adegree of imidization of about 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70,71, 72, 73, 74, or 75%, including increments therein, relative to theamount of maleic acid monomer present in the resin.

In some embodiments, the emulsion particles constitute 0-80% weight ofthe total solids of the aqueous composition. This includes 0-75%, 0-70%,0-65%, 0-60%, 5-80%, 5-75%, 5-70%, 5-65%, 5-60%, 10-80%, 10-75%, 10-70%,10-65%, 10-60%, 15-80%, 15-75%, 15-70%, 15-65%, 15-60%, 20-80%, 20-75%,20-70%, 20-65%, 30-80%, 30-75%, 30-70%, 30-65%, 50-80%, 50-75%, 50-70%,60-80%, or 70-80% weight of the total solids of the aqueous composition.In some embodiments, the emulsion particles constitute about 0, 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76,77, 78, 79, or 80% weight of the total solids of the aqueouscomposition.

In some embodiments, the emulsion particles are formed from initialpolymerization of acrylate and styrenic monomers in the presence of asurfactant prior to blending with the resin. In some embodiments, theemulsion particles are formed from polymerization of acrylate andstyrenic monomers in the presence of the resin.

In one aspect, a process is provided for preparing an aqueous solutionof a cycloimide-containing polymer. The process includes heating anaqueous solution of a cycloanhydride-containing polymer with a firstneutralizing agent at a ratio of cycloanhydride to neutralizing agent ofabout 1:1 to about 1:1.5 at a temperature and for a time sufficient toform the aqueous solution of the cycloimide-containing polymer having acycloimide to acid group ratio of about 1:2 to about 1.5:2. Thetemperature of the heating may be from about 130° C. to about 155° C.

In any of the above embodiments, the feed ratio of cycloanhydride toneutralizing agent is about 1:1. Such embodiments may be represented byScheme 2 which, and without being bound by theory, is believed to be themechanism through which the cycloimide containing polymer is prepared.Scheme 2 illustrates neutralization of a styrene,cycloanhydride-containing resin progressing through a ring-openedintermediate having both amide and acid groups. Although the acid groupsare formally shown as acid groups, it is likely that they are in factpartially neutralized with an ammonium counterion. Thus, uponneutralization there is an initial ring opening of the cycloanhydride toan amine-acid, while other anhydrides are simply hydrolyzed.Ring-closure to the cycloimide then occurs within the amide-acidpairing. As noted in Scheme 2, the resin is stable toward viscosityincreases. It is believed that such viscosity increases are at least inpart due to formation of other cycloimide groups. As there may be someformation of such groups, or ring closure to other cycloanhydridegroups, the stability is not absolute, but the rate at which such ringclosure occur is substantially low and substantial viscosity increasesare not observed, even at elevated temperatures of 150° C.

In any of the above embodiments, the cycloanhydride-containing polymermay be a styrene-maleic anhydride polymer, or an α-methylstyrene-maleicanhydride polymer. Within the cycloanhydride-containing polymer, a ratioof styrene or α-methylstyrene to cycloanhydride may be from about 1:1 toabout 3:1. This includes a ratio of about 1:1.

The cycloanhydride-containing polymer may include other repeat unitgroups as well that are derived from acrylate, methacrylate,diisobutylene, and other α-olefin monomers, or a combination of any twoor more thereof. In some embodiments, the cycloanhydride-containingpolymer does not include diisobutylene repeat units. Thus, the overallcycloanhydride-containing polymer may include a styrene-acrylate-maleicanhydride resin, an α-methylstyrene-acrylate-maleic anhydride resin, astyrene-methacrylate-maleic anhydride resin, anα-methylstyrene-methacrylate-maleic anhydride resin, astyrene-acrylate-maleic anhydride resin, anα-methylstyrene-acrylate-maleic anhydride resin, astyrene-diisobutylene-maleic anhydride resin, anα-methylstyrene-diisobutylene-maleic anhydride resin, or a combinationof any two or more thereof.

The process may also include a second neutralization step at the sametemperature as the first neutralization, or at a lower temperature. Inany of the above embodiments, the second neutralization may be conductedat a temperature from about 50° C. to about 130° C. This includes atemperature of about 70° C. to about 120° C., or from about 80° C. toabout 110° C. In any of the above embodiments, the temperature for thesecond neutralization may be about 90° C.

The first neutralization agent may be an amine represented by theformula NR²R³R⁴. In the formula, R², R³, and R⁴ are independently H,C₁₋₁₂ alkyl, or C₁₋₁₂ aryl. In any of the above embodiment, the firstneutralizing agent may be NH₃.

The second neutralization agent, or neutralizing agent, may be an alkalimetal hydroxide, alkali metal oxide, alkaline earth metal hydroxide,alkaline earth metal oxide, or an amine represented by the formulaNR²R³R⁴. Where the second neutralization agent is an amine, R², R³, andR⁴ are independently H, C₁₋₁₂ alkyl, or C₁₋₁₂ aryl. In some embodiments,the second neutralizing agent is NaOH, KOH, or NH₃.

As noted above, the process is to be conducted for a time sufficient toform the aqueous solution of the cycloimide-containing polymer. Thistime frame may be widely varied as the specific repeat units andcompositions of the polymer change. However, in some embodiments, thetime may be from about 1 hour to 5 hours.

The final pH of the aqueous solution aids in determining the stabilityof the solution. The pH of the aqueous solution therefore has a pH offrom about 7 to about 10. In some embodiments, the pH is from 8 to 9.

In the cycloimide-containing polymer, the molecular weight may bevaried, Lower molecular weights are preferred to avoid increases inviscosity due to increased molecular weight. Accordingly, in any of theabove embodiments, the imide-containing polymer may have a weightaverage molecular weight from about 5,000 g/mol to about 15,000 g/mol.

In some embodiments, provided herein are processes of preparing a resincut, the process including cutting a resin at a temperature of between80° C. and 150° C. by introducing the resin to an initial charge ofneutralizing amine of from 30% to 80% based on diacid equivalent ofmaleic anhydride units in the resin, wherein the resin is formed fromcomonomers including maleic anhydride and styrene; and the resin cut iswater-soluble. In further embodiments, 25% to 75% of the maleicanhydride units are imidized. In some embodiments, 25% to 75% of themaleic anhydride units are imidized, and the resin cut has a resultantdegree of neutralization of any carboxyl species of from 50% to 100%.

As noted above, the process provides for an aqueous solution havingviscosity that does not, or resists, increase over time. The targetviscosity for the aqueous solution may be such that it is workable as abase resin for the preparation of other coatings and compositions. Insome embodiments, the aqueous solution of the cycloimide-containingpolymer has a viscosity from about 10 cPs to about 500,000 cPs. In otherembodiments, the aqueous solution of the cycloimide-containing polymermay have a viscosity from about 100 cPs to about 5,000 cPs. Viscosity ofthe aqueous solution is also determined by the amount ofcycloimide-containing polymer that is present in the aqueous solution.In any of the above embodiments, the amount of cycloimide-containingpolymer that is present in the aqueous solution may be from about 10 wt% to about 35 wt %. This includes the cycloimide-containing polymerbeing present in the aqueous solution from about 25 wt % to about 30 wt%.

Another measure of the polymer properties are the glass transitiontemperature of the resultant polymers. In the above process, thecycloimide-containing polymer may have a Tg from about 130° C. to about230° C. In some embodiments of the above process, thecycloimide-containing polymer may have a Tg from about 150° C. to about230° C.

In another aspect, an aqueous solution of any of the abovecycloimide-containing polymers is provided. The aqueous solution may bedescribed by reference to the cycloimide-containing polymer describedabove. The aqueous solution may be described in terms of its viscosityor in terms of its resistance to viscosity increases over time. Forexample, the aqueous solution may exhibit an increase in viscosity ofless than 20% at ambient temperature for 90 days relative to theviscosity of the aqueous solution upon its preparation. In someembodiments, the actual viscosity is less important than viscositystability. Since measured viscosity is a strong function of absolutesolids, the solution viscosity can simply be reduced via dilution.However, once reduced, it is undesirable to the formulator if theviscosity increases further by some thickening mechanism. In particular,it is typically undesirable if the viscosity increase is such that[η_(t=90)/η_(t=0)] is >1.2, where η_(t=90) is the viscosity after 90days. Further, the aqueous solution may be a styrenecycloimide-containing polymer prepared from a styrenecycloanhydride-containing polymer, wherein the aqueous solution containsup to 30 wt % of the cycloimide-containing polymer and exhibits anincrease in viscosity of less than 20% at ambient temperature for 90days relative to the viscosity of the aqueous solution upon itspreparation.

The present embodiments, thus generally described, will be understoodmore readily by reference to the following examples, which are providedby way of illustration and are not intended to be limiting of thepresent technology in any way.

EXAMPLES

General.

In the examples that follow, SMA-1000 is a styrene maleic anhydride(MAH) polymer having a ratio of styrene to MAH of 1:1, and SMA-2000 is astyrene maleic anhydride (MAH) polymer having a ratio of styrene to MAHof 2:1

Example 1

Water (3729.5 g), a 60/40 blend of SMA-2000/SMA-1000 (1000 g, containing3.92 moles of anhydride) were charged to a reactor along with 270.5 g of28% aqueous ammonia (4.4 mol). The charged total mas of 5000.0 gcontained 20% solids. The calculated degree of neutralization (“DN”) was56.7% NH₃ on fully hydrolyzed anhydride. The mixture was cooked for 1hour at 155° C. The resulting mixture had a pH of 7.1 and a viscosity of500,000 cPs.

Four 100 g samples were then mixed with successively increasing aliquotsof aqueous NH₃ (for further neutralization) at the rate of 0.56 g per100 g. The viscosity and pH versus DN curves are shown in the FIGURE.

The wet sample (20.0% solids) was titrated in triplicate for remainingbase (either NH₃ or COO⁻). A wet base value (BV) of 28.8 was obtained.On dry solids the BV is 143.8. The calculated percent of imidesubstitution is 48.0%, assuming the ammonia strength to be 28% and noamide. The estimated DN on remaining carboxyl was 63%.

The resin was further neutralized and used to make a resin-supportedemulsion, which was then used to prepare a hot-mar, over-print varnish.The samples were tested at 54% and 64% resin on overall (46% and 36%acrylic emulsion) solids.

Example 2

SMA-1000 resin (1250 g) was charged to a reactor, followed by aqueousammonia (428.6 g; assumed 28.0% by weight active) and water (3324 g) toa total mass of 5000.0 g. The sample was cooked under agitation in theautoclave for 1 hour at 155° C. The resulting resin cut had a pH of 7.47and an initially measured viscosity of 88,000 cPs. The measured Tg was196.4° C. The product had 25% solids and a 56.7 DN NH₃.

The sample was titrated in triplicate and a wet BV of 43.0 was obtained,corresponding to an imidization of 51.3% on charged anhydride. The DN ofthe remaining ammonia on carboxyl was calculated at 63.8%, assuming noamide formation.

Example 3

Similar to Example 2, except the temperature was 130° C., and sampleswere pulled at 1 and 2 hours before concluding at 3 hours total cooktime. Each sample was tested for pH, viscosity, and AV. The Tg for the2-hour sample was measured by DSC to be 192.8° C. measurement via DSC.The product contained 25% solids with 56.7 DN (degree of neutralization)NH₃.

Example 4

Reaction of an SMA blend (60/40) (SMA2000/1000) at 24.0% charged solidswith 56.7 DN ammonia at 155 0° for 1 hour, then post-neutralized to 90DN on carboxyl. This trial was similar to Example 1, except that 80.0 gof aqueous ammonia was added to the resin cut after lowering the reactortemperature to 75° C.

Water (3475.5 g), a 60/40 blend of SMA-2000/SMA-1000 (1200 g; containing4.71 moles of anhydride) were charged to a reactor along with 324.5 g of28% aqueous ammonia (4.4 mol). The charged total mass of 5000.0 gcontained 24% solids. The reactor was held at 155° C. for 1 hour andthen cooled to 75° C. After removal of a 100 g sample, 80.0 g of NH₃(aq) was added to make the final solids to 23.6%. The pH was 8.5 and thefinal viscosity was 30,000 cPs. Utilizing the calculated final solids of23.6% and measured wet base value of 46.8, the degree of imidization wasderived to be 51.3%. The calculated DN on remaining carboxyl wasestimated to be 92.5 DN.

Example 5

To a 1000 mL emulsion reactor equipped with a condenser, stirrer, andnitrogen purge, was added 397.6 g of the autoclave resin cut of Example1 (at 20% solids) and 6.5 g of aqueous ammonia (used to adjust thedegree of neutralization to approximately 90%). The reactor was thenheated to 80° C., followed by addition of 1.4 g of ammonium persulfate(APS) dissolved in 18.6 g of deionized water (DIW), and the resultantmixture held for 3 minutes before beginning a monomer feed of 47.7 g ofmethyl methacrylate (MMA) and 190.9 g of ethyl acrylate (EA). Themonomer feed was pumped into the reactor at a rate of 2.65 g/min over 90minutes. At 45 minutes into the monomer feed, an APS co-feed was started(co-feed containing 0.35 g APS and 35.7 g water). The APS co-feed waspumped into the reactor at a rate of 0.72 g/min over 50 minutes. After95 minutes when both the monomer feed and ammonium persulfate co-feedhad ended, each line was flushed with 15.5 g of water.

The reactor was held at 80° C. for an additional 30 minutes. 1.0 g ofFe(II)-EDTA solution (prepared from 0.5 g Fe(II)sulfate, 0.3 gethylenediaminetetracetic acid (EDTA) in 100 g deionized water (DIW))was pipetted into the reactor, followed by 19.2 g t-BHP (t-butylhydroperoxide) solution (1 g t-BHP/18.2 g DIW) added to the reactor at apump rate of 0.96 g/min, with a simultaneously co-feed of 19.0 gisoascorbic acid (IAA) (1.0 g IAA/16.2 g DIW/1.8 g NH3(aq)) pumped at arate of 0.95 g/min. Both lines were flushed with 7.8 g DIW. The reactorwas then cooled to 25° C. and the emulsion was filtered through a 100micron filter bag. The resulting emulsion had a pH of 7.0, an initiallymeasured viscosity of 634 cPs. The measured solids was 40.0% and theparticle sizes were D_(v)=140 nm and D_(n)=111 nm, where D_(v) is thevolume average particle diameter, and D_(n) is the number averageparticle diameter.

A blend was then made using the emulsion of Example 5 and a resin cutfrom Example 1. The blend was made using a bench top mixer equipped witha mixing blade. In a beaker containing 317.9 g of Example 1, 250.0 g ofemulsion from Example 5 was added over 15 minutes under constantagitation until the emulsion and resin became a homogenous solution. Theresulting blend had a pH of 8.3, an initially measured viscosity of 35cPs, and solids of 28.95%.

A second blend was then made using the emulsion of Example 5 and a resincut of Example 1. The blend was made using a bench top mixer equippedwith a mixing blade. In a beaker containing 398.7 g of Example 1, 180.0g of the emulsion of Example 5 was added over 15 minutes under constantagitation until the emulsion and resin became a homogenous solution. Theresulting blend had a pH of 8.5, an initially measured viscosity of 32cPs, and a measured solids of 26.4%.

Example 6

To a 1000 mL emulsion reactor equipped with a condenser, stirrer, andnitrogen purge, were added 38.8 g of DIW and 396.7 g of the autoclaveresin cut of Example 4 (at 23.6% solids/degree of neutralization ofabout 85%). The reactor was then heated to 80° C. Then 1.7 g of APSdissolved in 9.6 g of DIW was charged and held for 3 minutes beforebeginning the monomer feed of 57.1 g of MMA and 228.6 g of EA. Themonomer feed was pumped into the reactor at a rate of 3.17 g/min over 90minutes. At 45 minutes into the monomer feed, an APS co-feed was started(co-feed containing 0.41 g APS and 42.8 g water). The APS co-feed waspumped into the reactor at a rate of 0.86 g/min over 50 minutes. After95 minutes when both the monomer feed and ammonium persulfate co-feedhad ended, each line was flushed with 9.6 g of water. The reactor washeld at 80° C. for an additional 30 minutes. A solution of 1.1 g ofFe(II)-EDTA (prepare from 0.5 g Fe(II)sulfate and 0.3 g EDTA in 100 gDIW) was pipetted into the reactor, followed by 10.9 g t-BHP solution(1.3 g t-BHP/9.6 g DIW) at a pump rate of 0.54 g/min, and a simultaneousco-feed of 12.8 g isoascorbic acid (1.1 g IAA/9.6 g DIW/2.1 g NH₃ aq) ata rate of 0.64 g/min. Both lines were flushed with 4.8 g DIW.

The reactor was then cooled to 25° C. and the emulsion was filteredthrough a 100 micron filter bag. The resulting emulsion had a pH of 7.2,an initially measured viscosity of 360,000 cPs, a measured solids of45.8% (calculated 46.0%) and measured particle sizes of Dv=160 nm,Dn=133 nm.

A blend was then made using the emulsion in Example 6 and the resin ofExample 4. The blend was made using a bench top mixer equipped with amixing blade. In a beaker, to 418.3 g of Example 4 and 18.5 g water,350.0 g of the emulsion of Example 6 was added over 15 min underagitation until the emulsion and resin became a homogenous solution. 29g of water was added to lower the solids to 31.50% (theoretical). Theresulting blend had a pH of 7.8, an initial measured viscosity of 1010cPs, and measured solids of 31.7%.

A second blend was then made using the emulsion in Example 6 and theresin of Example 4. The blend was made using a bench top mixer equippedwith a mixing blade. To a beaker containing 520.3 g of Example 4 and23.0 g water, 250.0 g of the emulsion of Example 6 was added over 15 minunder agitation until the emulsion and resin became a homogenoussolution. 22 g of water was then added to lower the solids to 28.5%(theoretical). The resulting blend had a pH of 7.7, an initiallymeasured viscosity of 1200 cPs, and a measured solids of 32.0%.

Example 7

To a 1000 mL emulsion reactor equipped with a condenser, stirrer, andnitrogen purge, 77.6 g of DIW, 444.7 g of autoclave resin cut Example(at 25% solids), and 6.9 g NH₃ aq.) (used to adjust the degree ofneutralization about 85%) was added. The reactor was then heated to 80°C. At temperature, 2.0 g of ammonium persulfate (APS) dissolved in 11.2g of DIW was charged and held for 3 minutes before beginning the monomerfeed of 66.7 g MMA and 266.9 g EA. The monomer feed was pumped into thereactor at a rate of 3.17 g/min over 90 minutes. At 45 minutes into themonomer feed, an APS co-feed was started (co-feed containing 0.5 g APSand 49.9 g water). The APS co-feed was pumped into the reactor at a rateof 1.01 g/min over 50 minutes. After 95 minutes when both the monomerfeed and the APS co-feed had ended, each line was flushed 11.2 g ofwater. The reactor was held at 80° C. for an additional 30 minutes. Asolution of 1.32 g of Fe(II)-EDTA (prepared from 0.5 g Fe(II)sulfate and0.3 g EDTA in 100 g water) was pipetted into the reactor followed by12.7 g t-BHP solution (1.5 g t-BHP/11.2 g DIW) at a pump rate of 0.63g/min, and a simultaneously co-feed of 15 g isoascorbic acid (1.3 gIAA/11.2 g DIW/2.5 g NH₃ (aq)) pumped at a rate of 0.75 g/min. Bothlines were flushed with 5.6 g DIW. The reactor was then cooled to 25° C.and the emulsion was filtered through a 100 micron filter bag. Theresulting emulsion had a pH of 7.3, an initial measured viscosity of 790cPs, a measured solids of 44.1%, and a measured particle size ofD_(v)=98 nm, D_(n)=81 nm.

A blend was made using the emulsion in Example 7 and the resin ofExample 2. The blend was made using a bench top mixer equipped with amixing blade. In a beaker, 674.0 g of the Example 2 resin was measured,over 15 min 350.0 g of emulsion Example 7 was added under agitationuntil the emulsion and resin became a homogenous solution. The resultingblend had a pH of 8.3, an initial measured viscosity of 145 cPs, andmeasured solids of 32% (calculated 30.7%).

Example 8

To a 1000 mL emulsion reactor equipped with a condenser, stirrer, andnitrogen purge, 494.3 g of autoclave resin cut Example 4 (at 22.6%solids/degree of neutralization of about 85%) was added along 24.7 gDIW. The reactor was then heated to 80° C.; once the reactor reachedtemperature, 2.0 g of ammonium persulfate (APS) dissolved into 11.4 g ofDIW was charged and held for 3 minutes before beginning the monomer feedof 153.5 g of styrene (STY) and 187.6 g of butyl acrylate (BA). Themonomer feed was pumped into the reactor at a rate of 3.79 g/min over 90minutes. At 45 minutes into the monomer feed, an APS co-feed was started(co-feed containing 0.5 g APS and 51.1 g water). The APS co-feed waspumped into the reactor at a rate of 1.03 g/min over 50 minutes. After95 minutes, when both the monomer feed and ammonium persulfate co-feedhad ended, each line was flushed 11.4 g of water. The reactor was heldat 80° C. for an additional 30 minutes. A solution of 1.35 g ofFe(II)-EDTA (prepared from 0.5 g Fe(II)sulfate, 0.3 g EDTA, with 100 g)was pipetted into the reactor; this was followed by 12.9 g t-BHPsolution (1.5 g t-BHP/11.4 g DIW) added to the reactor at a pump rate of0.65 g/min, and simultaneously co-feed of 15.3 g iso-ascorbic acid (1.4g IAA & 11.4 g DIW & 2.5 g NH₃ aq)) pumped at a rate of 0.77 g/min. Bothlines were flushed with 5.7 g DIW. The reactor was then cooled to 25° C.and the emulsion was filtered through a 100 micron filter bag. Theresulting emulsion had a pH of 8.0, an initially measured viscosity of183,000 cPs, a measured solids of 46.2% and measured particle sizes ofD_(v)=108 nm, D_(n)=78 nm.

A blend was then made using the emulsion in Example 8 and the resin ofExample 4. The blend was made using a bench-top mixer equipped with amixing blade. In a beaker, 548.3 g (22.6% solids) of Example 4 resinmeasured, over 15 min 250.0 g of the emulsion of Example 8 was addedunder agitation until the emulsion and resin became a homogenoussolution. The resulting blend had a pH of 8.2, an initial measuredviscosity of 6700 cPs, and measured solids of 30%.

Example 9

SMA-1000 (1560.0 g) and water (3737.3 g) were charged to a 2-gallonautoclave reactor. Ammonium hydroxide (28-29%, 702.3 g) was added to thereactor. The reactor was sealed and agitation begun at 250 RPM. Thereactor was heated to a set-point of 110° C., and t=0 was defined whenthe reactor reached 108° C. 200 g samples were removed at the end ofevery hour for 8 hours. The reactor was cooled and held at 50° C.overnight. The next morning, heating was commenced again at 110° C., andhourly removal of 200 g samples was continued until an approximate totaltime of 14 hours cook. A final wet acid value of ˜55.5 was measured forthe last sample. Wet base values were invariant, coming in at 58.6 (mgKOH/g resin).

Example 10

Resin Cut (RC) Dispersion Blend A (MMA/EA:20/80): To a 1400-mLwater-jacketed reactor equipped with a condenser, feed tube,thermocouple, and two three-blade impellers, water (57.77 g) and theautoclave resin cut of Example 9 (437.08 g) were charged. A nitrogenpurge was begun and the contents of the reactor were heated to 80° C.Once the contents reached 80° C., ammonium persulfate (1.29 g) dissolvedin water (7.37 g) was charged to the reactor, and the reactor was heldat temperature for three minutes. A monomer feed composed of methylmethacrylate (MMA, 43.8 g) and ethyl acrylate (EA, 175.2 g) was fed intothe reactor over 90 minutes. A secondary feed composed of ammoniumpersulfate (0.31 g) and water (32.85 g) began 45 minutes after themonomer feed began. The secondary feed was fed over 50 minutes. Reactionwas then held at temperature for 30 minutes. After this 30-minuteperiod, iron sulfate/EDTA complex (0.91 g) and tBHP (0.87 g) werecharged to the reactor. Immediately after charging the tBHP, a feed, thereducing agent, composed of IAA acid (1.10 g), water (8.98 g), andammonium hydroxide (1.7 g) was fed over 20 minutes. After this 20-minutefeed, reaction was held at temperature for 10 minutes. The contents werecooled to 50° C., then filtered through a 150-mesh screen attemperature. Grit was negligible. Note: dispersion was too viscous tofilter at room temperature. η>>100,000 cPs (spindle 4, 0.3 rpm, measuredat 25° C.), Dv=246.5 nm, Dn=192.5 nm, Ð=1.28, Solids=41.18%.

Example 11

RC Dispersion Blend B1 (MMA/EA:20/80): The autoclave resin cut ofExample 9 (353.34 g) was charged to a 1400-mL water-jacketed reactorequipped with a condenser, feed tube, thermocouple, and threethree-blade impellers. A nitrogen purge was begun and the contents ofthe reactor were heated to 80° C. Once the contents reached 80° C.,ammonium persulfate (1.04 g) dissolved in water (5.96 g) was charged tothe reactor, and the reactor was held at temperature for three minutes.A monomer feed composed of methyl methacrylate (MMA, 35.4 g) and ethylacrylate (EA, 141.6 g) was fed into the reactor over 90 minutes. Asecondary feed composed of ammonium persulfate (0.25 g) and water (26.56g) began 45 minutes after the monomer feed began. The secondary feed wasfed over 50 minutes. The reaction was then held at temperature for 30minutes. After this 30-minute period, iron sulfate/EDTA complex (0.75 g)and tBHP (0.70 g) was charged to the reactor. Immediately after the tBHPaddition, a feed, the reducing agent, composed of IAA acid (0.90 g),water (7.28 g), and ammonium hydroxide (1.40 g) was fed over 20 minutes.After this 20-minute feed, the reactor kept at temperature. A 20-gsample was removed from the reactor for characterization. Due to thesize of sample, pH, viscosity, and particle size were not measured.Solids=42.94%.

Example 12

RC Dispersion Blend C (BA:100): The process for was the same aspreviously described for RC Dispersion Blend A except the monomer feedwas composed of only butyl acrylate (BA, 218.95 g). RC Dispersion BlendC was cooled to 25° C. after the final temperature hold and was filteredthrough a 150-mesh screen. Grit was negligible. η=2,439 cPs (spindle 4,60 rpm). Dv=108.5 nm, Dn=92.7 nm, Ð=1.17, Solids=42.19%.

Example 13

RC Dispersion Blend D (BA:100): The autoclave resin cut of Example 9(218.95 g) was charged to a 1400-mL water-jacketed reactor equipped witha condenser, feed tube, thermocouple, and three three-blade impellers. Anitrogen purge was begun, and the contents of the reactor were heated to80° C. Once the contents reached 80° C., ammonium persulfate (0.96 g)dissolved in water (5.46 g) were charged to the reactor, and the reactorwas held at temperature for three minutes. A monomer feed composed ofbutyl acrylate (BA, 162.2 g) was fed into the reactor for 90 minutes. Asecondary feed composed of ammonium persulfate (0.23 g) and water (24.36g) began 45 minutes after the monomer feed was started. The secondaryfeed was for 50 minutes. The reaction was then held at temperature for30 minutes. After this 30-minute period, iron sulfate/EDTA complex (0.68g) and tBHP (0.6 g) were charged to the reactor. Immediately after thetBHP addition, a feed, the reducing agent, composed of IAA acid (0.82g), water (6.69 g), and ammonium hydroxide (1.20 g) was fed over 20minutes. After this 20-minute feed, the reactor was kept at temperature.A 20-g sample was removed from the reactor for characterization. Due tothe size of the sample, pH was not measured. η=18,596 cPs (spindle 4, 30rpm), Dv=110.2 nm, Dn=90.9 nm, Ð=1.21, Solids=45.72%.

Example 14

RC Dispersion Blend E1 (MMA/EA/BA:10/40/50): Water (52.37 g) and theautoclave resin cut of Example 9 (322.51 g) was charged to a 1400-mLwater-jacketed reactor equipped with a condenser, feed tube,thermocouple, and three three-blade impellers. A nitrogen purge wasbegun, and the contents of the reactor were heated to 80° C. Once thecontents reached 80° C., ammonium persulfate (0.95 g) dissolved in water(5.46 g) was charged to the reactor, and the reactor was held attemperature for three minutes. A monomer feed composed of methylmethacrylate (MMA, 16.2 g), ethyl acrylate (EA, 64.6 g), and butylacrylate (BA, 80.80 g) was fed into the reactor over 90 minutes. Asecondary feed composed of ammonium persulfate (0.24 g) and water (24.31g) was begun 45 minutes after the monomer feed began. The secondary feedwas fed over 50 minutes. The reaction was then held at temperature for30 minutes. After this 30-minute period, iron sulfate/EDTA complex (0.67g) and tBHP (0.60 g) was charged to the reactor. Immediately after thetBHP addition, a feed, the reducing agent, composed of IAA acid (0.81g), water (6.67 g), and ammonium hydroxide (1.20 g) was fed over 20minutes. After this 20-minute feed, the reactor was kept at temperature.A 20-g sample was removed from the reactor for characterization. Due tothe size of sample, pH was not measured. η=18,596 cPs (spindle 4, 30rpm), Dv=126.5 nm, Dn=108.1 nm, Ð=1.17, Solids=41.39%.

Example 15

RC Dispersion Blend E2 (MMA/EA/BA:10/40/50): The process was the same asthat previously described for Example 14. pH was not measured to be 8.8,Dv=135 nm, Dn=119 nm, Solids=33.2%.

Example 16

Back-blended Dispersion A2: At 50° C., RC Dispersion Blend A of Example10 (230.0 g) was blended with the resin cut of Example 9 (323.6 g).Deionized water (5.4 g) and Calsoft L-40 (1.06 g, 20% active) were alsoblended in. The overall polymer solids was 34%, comprised of 58% resin,with 0.19 PHW of Calsoft.

Example 17

Back-blended Dispersion A1: At 50° C., RC Dispersion Blend A of Example10 (230.0 g) was blended with the resin cut of Example 9 (323.6 g).Deionized water (17.7 g) and Calsoft L-40 (4.43 g, 20% active) were alsoblended in. The overall polymer solids was 33%, comprised of 58% resin,with 0.78 PHW of Calsoft.

Example 18

Back-blended Dispersion B1: At 85° C., RC Dispersion Blend B1 of Example11 (203.6 g) was blended with the resin cut of Example 9 (300.0 g).Deionized water (10.80 g) and Calsoft L-40 (1.32 g, 20% active) werealso blended in. The overall polymer solids was 33%, comprised of 65%resin, with 0.25 PHW of Calsoft.

Example 19

Back-blended Dispersion B2: At 85° C., RC Dispersion Blend B1 of Example11 (579.0 g) was blended with the resin cut of Example 9 (853.1 g).Calsoft L-40 (5.98 g, 20% active) was also blended in. The overallpolymer solids was 34%, comprised of 65% resin, with 0.42 PHW ofCalsoft.

Example 20

Back-blended Dispersion C1: At 50° C., RC Dispersion Blend C of Example12 (230.0 g) was blended with the resin cut of Example 9 (208.4 g).Deionized water (22.1 g) and Calsoft L-40 (1.16 g, 20% active) were alsoblended in. The overall polymer solids was 33%, comprised of 58% resin,with 0.25 PHW of Calsoft.

Example 21

Back-blended Dispersion C2: At 50° C., RC Dispersion Blend C of Example12 (203.6 g) was blended with the resin cut of Example 9 (208.4 g).Deionized water (8.80 g) and Calsoft L-40 (4.48 g, 20% active) were alsoblended in. The overall polymer solids was 34%, comprised of 58% resin,with 1.0 PHW of Calsoft.

Example 22

Back-blended Dispersion C3: At 50° C., RC Dispersion Blend C of Example12 (230.0 g) was blended with the resin cut of Example 9 (323.6 g).Calsoft L-40 (5.52 g, 20% active) was also blended in. The overallpolymer solids was 33%, comprised of 65% resin, with 0.99 PHW ofCalsoft.

Example 23

Back-blended Dispersion D: At 50° C., RC Dispersion Blend D of Example13 (528.6 g) was blended with the resin cut of Example 9 (795.3 g).Calsoft L-40 (2.90 g, 20% active) was also blended in. The overallpolymer solids was 34%, comprised of 65% resin, with 0.22 PHW ofCalsoft.

Example 24

Back-blended Dispersion E1: At 50° C., RC Dispersion Blend E1 of Example14 (577.0 g) was blended with the resin cut of Example 9 (636.0 g). To315.4 g of the resultant blend, deionized water (1.5 g) and Calsoft L-40(1.98 g) were also blended in. The overall polymer solids was 33.5%,comprised of 61.5% resin, with 0.63 PHW of Calsoft.

Example 25

Back-blended Dispersion E2: At 50° C., RC Dispersion Blend E2 of Example15 (580.0 g) was blended with the resin cut of Example 9 (640.0 g). To598.3 g of the resultant blend, deionized water (2.0 g) and Calsoft L-40(3.71 g) were also blended in. The overall polymer solids was 33.5%,comprised of 61.5% resin, with 0.62 PHW of Calsoft.

Example 26

Characterization of back-blended dispersion blends from Examples 16-25is shown in Table 1.

TABLE 1 Exploration of Dispersion Blends Emulsion Monomer Target ResinCalsoft Composition (%) solids support L-40 Viscosity (cPs) Blend MMA EABA % level (%) level (%) 0 day 1 day 14 day 21 day 28 day Disp. Blend A₁20 80 33 58 1.0  2.130  3.279  20.046 106.000 159.000 Disp. Blend A₂ 2080 34 58 0.25  4.589  11.558 141.000 451.000 770.000 Disp. Blend B₁ 2080 33 65 0.25  4.119  7.838  47.000  80.000 111.000 Disp. Blend B₂ 20 8034 65 1.0  4.079  14.297  63.000 136.000 128.000 Disp. Blend C₁ 100 3358 0.25 149.5 117.0  96.5 106.5 200.5 Disp. Blend C₂ 100 34 58 1.0 206.5137.0 145.0 219.0 261.5 Disp. Blend C₃ 100 33 65 1.0 271.4 220.5 221.0324.5 305.0 Disp. Blend D 100 34 65 0.25  91.0 743.8  1.202  1.048 1.278 Disp. Blend E₁ 10 40  50 33.5 61.5 0.625 500  1.222  2.064  3.112 2.511 Disp. Blend E₂ 10 40  50 33.5 61.5 0.625 489.9  1.230  1.524 2.740  2.740

While certain embodiments have been illustrated and described, it shouldbe understood that changes and modifications can be made therein inaccordance with ordinary skill in the art without departing from thetechnology in its broader aspects as defined in the following claims.

The embodiments, illustratively described herein may suitably bepracticed in the absence of any element or elements, limitation orlimitations, not specifically disclosed herein. Thus, for example, theterms “comprising,” “including,” “containing,” etc. shall be readexpansively and without limitation. Additionally, the terms andexpressions employed herein have been used as terms of description andnot of limitation, and there is no intention in the use of such termsand expressions of excluding any equivalents of the features shown anddescribed or portions thereof, but it is recognized that variousmodifications are possible within the scope of the claimed technology.Additionally, the phrase “consisting essentially of” will be understoodto include those elements specifically recited and those additionalelements that do not materially affect the basic and novelcharacteristics of the claimed technology. The phrase “consisting of”excludes any element not specified.

The present disclosure is not to be limited in terms of the particularembodiments described in this application. Many modifications andvariations can be made without departing from its spirit and scope, aswill be apparent to those skilled in the art. Functionally equivalentmethods and compositions within the scope of the disclosure, in additionto those enumerated herein, will be apparent to those skilled in the artfrom the foregoing descriptions. Such modifications and variations areintended to fall within the scope of the appended claims. The presentdisclosure is to be limited only by the terms of the appended claims,along with the full scope of equivalents to which such claims areentitled. It is to be understood that this disclosure is not limited toparticular methods, reagents, compounds compositions or biologicalsystems, which can of course vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting.

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, particularly in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” and the like,include the number recited and refer to ranges which can be subsequentlybroken down into subranges as discussed above. Finally, as will beunderstood by one skilled in the art, a range includes each individualmember.

All publications, patent applications, issued patents, and otherdocuments referred to in this specification are herein incorporated byreference as if each individual publication, patent application, issuedpatent, or other document was specifically and individually indicated tobe incorporated by reference in its entirety. Definitions that arecontained in text incorporated by reference are excluded to the extentthat they contradict definitions in this disclosure.

Other embodiments are set forth in the following claims.

What is claimed is:
 1. An aqueous composition comprising (a) asolubilized cycloimide-containing resin formed from comonomerscomprising maleic anhydride and substituted ethylenic comonomers,wherein (i) the resin comprises a cycloimide group and a partiallyneutralized maleamide-acid species; and (ii) the resin has an oxygencontent of from about 5% to about 30%, an acid value of at least 60 mgKOH/g on dry solids, and an amine base value of at least 60 mg/KOH ondry solids; (iii) the resin has a number average molecular weight ofabout 1,000 D to about 10,000 D; and (iv) the substituted ethyleniccomonomers comprise styrene; and (b) emulsion particles which constitute0-80% weight of the total solids.
 2. The aqueous composition of claim 1,wherein the ratio of styrene to maleic anhydride in the average molarrepeat unit of the resin is from 1:1 to 5:1.
 3. The aqueous compositionof claim 1, wherein the substituted ethylenic comonomers furthercomprise C₆-C₂₀ α-olefins; the resin has a percentage of styrene in thesubstituted ethylenic comonomers of from 0% to 80%; and maleic anhydrideis 33% to 50% of the average molar repeat unit of the resin.
 4. Theaqueous composition of claim 1, wherein the resin further compriseshydrolyzed diacid; the maleamide-acid species is partially neutralizedby a neutralizing amine; the neutralizing amine comprises ammonia or aprimary amine; and the resin has a degree of neutralization of themaleamide-acid species and the hydrolyzed diacid of at least 50%.
 5. Theaqueous composition of claim 2, wherein the resin has a degree ofimidization of from about 25 mol % to about 75 mol % relative to theamount of maleic anhydride monomer present in the resin.
 6. The aqueouscomposition of claim 2, wherein the resin has a degree of imidization offrom about 25 mol % to about 50 mol % range relative to the amount ofmaleic anhydride monomer present in the resin.
 7. The aqueouscomposition of claim 1, wherein the resin is formed from substitutedethylenic comonomers comprising acrylic acid, methacrylic acid, styrene,alpha-methyl styrene and maleic anhydride.
 8. The aqueous composition ofclaim 1, wherein the emulsion particles are formed from initialpolymerization of acrylate and styrenic monomers in the presence of asurfactant prior to blending with the resin.
 9. The aqueous compositionof claim 1, wherein the emulsion particles are formed frompolymerization of acrylate and styrenic monomers in the presence of theresin.